The present invention relates to systems and devices for cleaning floors and other surfaces, and more particularly to cleaning tool heads and cleaning tool head attachments used at the interface of the system and surface.
Cleaning systems that circulate and spray liquids are widely used for cleaning carpets, upholstery, fabric, wallcoverings and hard surfaces such as floors of concrete and ceramic tile. In one such system, known as continuous flow recycling, a liquid cleaning solution is sprayed toward the surface being cleaned. Simultaneously a vacuum source creates a high velocity airstream that draws the atomized liquid toward the surface, along the surface (or into the material in the case of carpeting), then upwardly away from the surface. This extracts soil, debris and other foreign matter along with the cleaning solution. This type of system is disclosed in U.S. Pat. No. 5,555,598 (Grave et al) issued Sep. 17, 1996, which is incorporated herein by reference.
With particular reference to FIGS. 15 and 16 of the '598 patent, a cleaning tool head can have a shell adapted particularly for cleaning hard surfaces such as ceramic tile, concrete and linoleum. Along a lower portion of its forward wall and opposite side walls, the shell is formed of a porous material, e.g. a carpet pad. This facilitates entry of air into an intake compartment inside the shell.
By contrast, the rear wall at least a lower portion adjacent an evacuation compartment inside the shell, is flexible and non-porous. This creates a wiping action like a squeegee against the surface being cleaned, to substantially prevent passage of air directly into the evacuation compartment from outside of the shell. As a result, virtually all air that enters the area beneath the shell enters the intake compartment rather than the exhaust compartment, which facilitates recovery of the cleaning solution and extraction of foreign matter from the surface being cleaned.
Although this approach is effective for cleaning a substantially planar surface, the rear wall even when flexible has limited capability to conform to deviations from surface planarity. Such deviations include, for example, the uniformly spaced apart grooves or depressions where group is applied between adjacent ceramic tiles. Deviations also can include cracks or other unintended surface discontinuities. In either event the flexible, non-porous rear wall of the shell, typically having a linear bottom edge, cannot conform to the surface. The resulting gaps between the rear wall and surface admit air directly into the exhaust compartment, allowing liquid cleaning solution to escape the tool head area and tending to reduce cleaning tool head efficiency.
Therefore, it is an object of the present invention to provide a cleaning system with a cleaning tool head shell that incorporates a barrier, at least along and adjacent the evacuation compartment, that conforms to surface irregularities to more effectively prevent air from entering the shell from certain areas immediately around the shell.
Another object is to provide a cleaning tool head that incorporates a fluid-flow barrier disposed between the tool head and the surface during cleaning, that more closely conforms to surface irregularities and thus provides an improved seal against passage of air and fluids.
A further object is to provide an adapter suitable for removable attachment to cleaning tool heads, to improve the efficiency of such tool heads when used to clean hard surfaces with irregular contours.
Yet another object is to provide a cleaning tool head or a vacuum tool head with an edge region that is substantially non-porous to resist air inflow, while capable of engaging a surface in a conforming manner to afford better control of air entry at the tool head perimeter.